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Diffstat (limited to 'fs/btrfs/transaction.c')
-rw-r--r--fs/btrfs/transaction.c39
1 files changed, 24 insertions, 15 deletions
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 874e4394df86..0bf42dccb041 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -56,12 +56,17 @@ static struct kmem_cache *btrfs_trans_handle_cachep;
* | Call btrfs_commit_transaction() on any trans handle attached to
* | transaction N
* V
- * Transaction N [[TRANS_STATE_COMMIT_START]]
+ * Transaction N [[TRANS_STATE_COMMIT_PREP]]
+ * |
+ * | If there are simultaneous calls to btrfs_commit_transaction() one will win
+ * | the race and the rest will wait for the winner to commit the transaction.
+ * |
+ * | The winner will wait for previous running transaction to completely finish
+ * | if there is one.
* |
- * | Will wait for previous running transaction to completely finish if there
- * | is one
+ * Transaction N [[TRANS_STATE_COMMIT_START]]
* |
- * | Then one of the following happes:
+ * | Then one of the following happens:
* | - Wait for all other trans handle holders to release.
* | The btrfs_commit_transaction() caller will do the commit work.
* | - Wait for current transaction to be committed by others.
@@ -112,6 +117,7 @@ static struct kmem_cache *btrfs_trans_handle_cachep;
*/
static const unsigned int btrfs_blocked_trans_types[TRANS_STATE_MAX] = {
[TRANS_STATE_RUNNING] = 0U,
+ [TRANS_STATE_COMMIT_PREP] = 0U,
[TRANS_STATE_COMMIT_START] = (__TRANS_START | __TRANS_ATTACH),
[TRANS_STATE_COMMIT_DOING] = (__TRANS_START |
__TRANS_ATTACH |
@@ -1982,7 +1988,7 @@ void btrfs_commit_transaction_async(struct btrfs_trans_handle *trans)
* Wait for the current transaction commit to start and block
* subsequent transaction joins
*/
- btrfs_might_wait_for_state(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_might_wait_for_state(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
wait_event(fs_info->transaction_blocked_wait,
cur_trans->state >= TRANS_STATE_COMMIT_START ||
TRANS_ABORTED(cur_trans));
@@ -2129,7 +2135,7 @@ static void add_pending_snapshot(struct btrfs_trans_handle *trans)
return;
lockdep_assert_held(&trans->fs_info->trans_lock);
- ASSERT(cur_trans->state >= TRANS_STATE_COMMIT_START);
+ ASSERT(cur_trans->state >= TRANS_STATE_COMMIT_PREP);
list_add(&trans->pending_snapshot->list, &cur_trans->pending_snapshots);
}
@@ -2153,7 +2159,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
ktime_t interval;
ASSERT(refcount_read(&trans->use_count) == 1);
- btrfs_trans_state_lockdep_acquire(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_trans_state_lockdep_acquire(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
clear_bit(BTRFS_FS_NEED_TRANS_COMMIT, &fs_info->flags);
@@ -2213,7 +2219,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
}
spin_lock(&fs_info->trans_lock);
- if (cur_trans->state >= TRANS_STATE_COMMIT_START) {
+ if (cur_trans->state >= TRANS_STATE_COMMIT_PREP) {
enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED;
add_pending_snapshot(trans);
@@ -2225,7 +2231,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
want_state = TRANS_STATE_SUPER_COMMITTED;
btrfs_trans_state_lockdep_release(fs_info,
- BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
ret = btrfs_end_transaction(trans);
wait_for_commit(cur_trans, want_state);
@@ -2237,9 +2243,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
return ret;
}
- cur_trans->state = TRANS_STATE_COMMIT_START;
+ cur_trans->state = TRANS_STATE_COMMIT_PREP;
wake_up(&fs_info->transaction_blocked_wait);
- btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
if (cur_trans->list.prev != &fs_info->trans_list) {
enum btrfs_trans_state want_state = TRANS_STATE_COMPLETED;
@@ -2260,11 +2266,9 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
btrfs_put_transaction(prev_trans);
if (ret)
goto lockdep_release;
- } else {
- spin_unlock(&fs_info->trans_lock);
+ spin_lock(&fs_info->trans_lock);
}
} else {
- spin_unlock(&fs_info->trans_lock);
/*
* The previous transaction was aborted and was already removed
* from the list of transactions at fs_info->trans_list. So we
@@ -2272,11 +2276,16 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans)
* corrupt state (pointing to trees with unwritten nodes/leafs).
*/
if (BTRFS_FS_ERROR(fs_info)) {
+ spin_unlock(&fs_info->trans_lock);
ret = -EROFS;
goto lockdep_release;
}
}
+ cur_trans->state = TRANS_STATE_COMMIT_START;
+ wake_up(&fs_info->transaction_blocked_wait);
+ spin_unlock(&fs_info->trans_lock);
+
/*
* Get the time spent on the work done by the commit thread and not
* the time spent waiting on a previous commit
@@ -2586,7 +2595,7 @@ lockdep_release:
goto cleanup_transaction;
lockdep_trans_commit_start_release:
- btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_START);
+ btrfs_trans_state_lockdep_release(fs_info, BTRFS_LOCKDEP_TRANS_COMMIT_PREP);
btrfs_end_transaction(trans);
return ret;
}